JPS581673Y2 - Fuel pump - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a fuel pump.

As shown in FIG. 1, a conventional fuel pump has a lower body 5 that includes a diaphragm 1, a diaphragm spring 2, a rocker arm 3, and a return spring 4, an inlet valve 6, and an outlet valve 7, and has suction and discharge passages 8, 9, and a cap 13 that is fixed to the upper part of the upper body and forms an air chamber 11 with a diaphragm 12.

In the conventional fuel pump having such a configuration, when the lift amount increases due to the movement of the eccentric cam 14 provided on the camshaft of the engine, the rocker arm 3 rotates counterclockwise in the figure, causing the pull rod 15 to rotate. The diaphragm 1 is pulled downward by overcoming the spring force of the diaphragm spring 2.

At this time, the inlet valve 6 opens and sucks fuel into the pump chamber 16 above the diaphragm 1.

When the eccentric cam 14 further rotates and its lift amount decreases, the rocker arm 3 is returned by the spring force of the return spring 4, and together with the released pull rod 15, the diaphragm 1 is pushed back by the spring force of the diaphragm spring 2, and the pump A series of operations is performed in which the fuel in the chamber 16 pushes open the outlet valve 7 and is sent to the discharge passage 8.

However, the conventional fuel pump with the above configuration has a large number of parts, and each member is molded from a non-ferrous alloy such as aluminum or sintered lead, so the upper body 10 is extremely large for the required pump chamber. This increases the weight, and the temperature of the atmosphere is likely to be transmitted to the suction chamber and discharge chamber, resulting in poor heat resistance.

The present invention was proposed in view of the above-mentioned drawbacks of the conventional technology, and its purpose is to provide a fuel pump that is lightweight, is not easily affected by temperature, has a simple structure, and has a low floor. It is in.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

In describing the embodiment of the present invention, the same components as those of the conventional example shown in FIG.

The main differences between the embodiment of the present invention shown in FIGS. 2 and 3 and the conventional example shown in FIG.
Inside, there are a suction chamber 8A, a discharge chamber 9A and a pump chamber 1.
An annular groove 17a is provided at the point where the partition block 17 molded from synthetic resin or non-ferrous alloy casting forming the 6A is accommodated, and at the outer periphery of the partition block 17. An annular sealed air chamber 18 sealed from the atmosphere is formed between the upper body 10A and the inner circumferential surface 10a.

Therefore, the configuration of this embodiment will be explained in detail below.

In this example, the fuel pump has an inlet vibe 26
and an upper body IOA made of a cylindrical thin steel plate with an outlet vibe 27 protruding in the axial direction.

The upper body 10A is housed inside the upper body 10A, and is made of metal and has a cylindrical shape with a bottom.The interior thereof is divided into two in the radial direction, and a suction chamber 8A and a discharge chamber are located at positions corresponding to the inlet vibe 26 and the outlet vibe 2γ. A partition block 17 having a partition plate 17' that separates a chamber 9A, a diaphragm 1 forming a pump chamber 16A on the lower side of the partition block 17, and a diaphragm 1 that alternately opens and closes due to the vertical movement of the diaphragm 1 to prevent the above-mentioned suction. Inlet valves 6 are provided at the bottoms 8a and 9a of the suction chamber 8A and the discharge chamber 9A to send the fuel introduced into the chamber 8A to the discharge chamber 9A and outlet vibe 27 via the pump chamber 16A. and an outlet valve 7, and an annular sealed air chamber 18 is formed between the annular groove 17a provided for the row of the partition blocks 17 and the inner circumferential surface 10a of the upper body 10A. has been done.

The partition block 17 is molded from a synthetic resin material or a non-ferrous alloy casting in order to reduce the weight of the fuel pump itself and to increase the heat insulation effect from the fifth row section.

An inlet vibe 26 and an outlet vibe 27 are inserted into the suction chamber 8A and the discharge chamber 9A at the upper part of the upper body 10A, and an air chamber 24.25 is installed at the upper part of the suction chamber 8A and the discharge chamber 9A. It is fixedly installed so that it can be formed.

Note that, in order to reduce pump pulsation, the discharge chamber 9A is desirably formed to have a larger volume than the suction chamber 8A.

In addition, bolts 19.19 are installed in the above-mentioned bulkhead block 17 at different distances from the center to prevent misassembly, and these bolts 19.19 are attached to the bolts formed on the upper surface of the upper body 10A. protrude outward from the hole,
By tightening the nuts 20.20, the bulkhead block 17 is attached in a suspended state inside the upper body 10A.

Further, the seal member 21 fitted into the annular recess 22 formed along the upper surface of the partition block 17 comes into contact with the upper inner wall of the upper body IOA to seal the space between it and the upper inner wall. Similarly to the seal member 21, the seal member 23 arranged around the lower part of the partition block 11 is also for sealing between the upper body 10A and the partition block 17. be.

Next, the operation of the present invention having the following configuration will be explained.

First, when the diaphragm 1 is moved up and down, the fuel drawn into the suction chamber 8A from the inlet vibe 26 passes through the inlet valve 6 and into the pump chamber 16A due to this up and down movement.
- from its pump chamber 16A to outlet valve 7
and is sent into the discharge chamber 9A.

-The fuel sent to the discharge chamber 9A is
After the discharge motive force is absorbed by the air chamber 25 formed above the liquid level inside, the liquid is discharged from the discharge chamber 9A to the outlet vibe 27.

As described above, in the present invention, the suction chamber 8A and the discharge chamber 9A
The partition block 17 forming the upper body 10A
The annular grooves 17a provided for the rows of the partition blocks 17 form a gap between the inner circumferential surface 10a of the upper body IOA and the partition blocks 11. Since the annular sealed air chamber 18 is formed in the partition wall block 11 itself and the annular sealed air chamber 18, the partition wall block 11 itself and the annular sealed air chamber 18 act as insulation from the normal temperature.

Therefore, it is possible to make it difficult for the external atmospheric temperature to be transmitted to the fuel in the suction chamber 8A and the discharge chamber 9A.

Therefore, even in a high-temperature atmosphere, the fuel in the suction chamber 8A and the discharge chamber 9A is heated and vaporized, so that it is possible to effectively prevent deterioration of pump performance, such as causing so-called vapor lock.

Further, since the partition block 1T is molded from a synthetic resin material or a non-ferrous alloy casting, the weight of the fuel pump can be further reduced, and the heat insulation effect can also be further improved.

As is clear from the above description, the present invention forms an annular sealed air chamber between the inner peripheral surface of the upper body and the inner peripheral surface of the upper body by an annular groove provided on the outer periphery of the partition block housed within the upper body. Since the fuel pump is constructed as shown in FIG.

Further, in the present invention, since the partition block is molded from a synthetic resin material or a non-ferrous alloy casting, it is possible to provide a fuel pump that is further lightweight, inexpensive, and has improved heat resistance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional fuel pump, FIG. 2 is a sectional view showing an embodiment of the present invention, and FIG. 3 is a sectional view showing essential parts of the present invention. 1...Diaphragm, 6...Inlet valve, 7
... Outlet valve, 8A... Suction chamber, 9A.
...Discharge chamber, 8a, 9a...bottom, 10A...upper body, 10a...inner peripheral surface, 16A...pump chamber, 17...partition block, 17a...annular groove, 1
7'... Partition plate, 18... Annular sealed air chamber-24,
25...Air chamber 25...Inlet vibe, 27...Outlet vibe.

Claims (2)

[Scope of utility model registration request] (1) An upper body made of a cylindrical thin steel plate from which an inlet pipe and an outlet pipe protrude in the axial direction; a partition block having a partition plate that is divided into two to separate a suction chamber and a discharge chamber at positions corresponding to the inlet pipe and outlet pipe; a diaphragm forming a pump chamber on the lower side of the partition block; an inlet valve provided at the bottom of the suction chamber and the discharge chamber to alternately open and close as the valve moves up and down to send the fuel introduced into the suction chamber through the pump chamber to the discharge chamber and the outlet pipe; and an outlet valve, and an annular sealed air chamber is formed between the inner peripheral surface of the upper body and the annular groove provided on the circumference A of the partition wall block. (2) The fuel pump according to claim 1, wherein the partition wall block is made of a synthetic resin material or a non-ferrous alloy casting.